Keep away from rear ported speakers in that size room. That’s why I suggested the Spendor A5r ( 2 1/2 way ) with sealed woofers! I’ve owned that speaker and found it to be an excellent performer!
The A4s are rear ported but they really don’t need that much space. I heard them in a room similar to the OPs. They were only a couple feet from the walls and no bass boom or overhang whatsoever. They sound sort of like a ProAc/A5 love child.